The present invention relates to apparatus for assuming and maintaining secure control of an aircraft in the event of an intended, attempted or actual attack upon the pilot(s) of the aircraft, the aircraft in general, or in the event of incapacity of the pilot(s). As is well known, terrorists and hijackers sometimes attempt to assume control of an aircraft by intimidating either the passengers and/or the crew. Once the attacker (terrorist or hijacker) takes control of an aircraft, he or she may cause it to fly to an inappropriate destination or may even cause the aircraft to crash.
The U.S. Pat. No. 6,917,863 discloses a method and system for assuming and maintaining secure remote control of an aircraft in the event of an actual or potential aircraft hijacking or incapacity of the pilot(s) due to illness or injury. The U.S. Patent Publication No. US2006/0032978 discloses a number of scenarios which, in the event of a hijacking or other incapacity of the pilot(s), entail an early autopilot/flight management computer control phase, followed by a later remote pilot control phase, whereby personnel on the ground or in another aircraft can assist in bringing the aircraft down for a safe landing at a desired location. The U.S. patent application Ser. No. 11/318,180 discloses and claims a method and system for disabling on-board pilot control of a non-fly-by-wire aircraft in the event of an emergency condition.
In the event of a hijacking, it is imperative that, once an emergency condition is declared, no one on board the aircraft (including the attackers) be allowed to influence or control the flight path of the aircraft. The aforementioned patent and patent applications disclose various methods of interrupting on-board pilot control of the aircraft, and operating the aircraft either automatically, with the aid of an autopilot and/or flight control system, or by a remote off-board (off-aircraft) human pilot.
Whether the aircraft be entirely electronically controlled or at least partially mechanically controlled, it has what will be termed hereafter an “aircraft control system” for controlling the various controlled components, such as the aircraft attitude control surfaces or the aircraft engine throttle(s). This aircraft control system is controlled either by the on-board pilot of the aircraft or by an alternate source of control such as an autopilot or a flight control system or even a remote off-aircraft pilot. The present invention relates to the apparatus, principally electronic, for disabling on-board pilot operation of the aircraft and transferring aircraft operation to the alternate source of control in the event of a hijacking. Hereinbelow, “hijacking” is intended to refer to any or all of (a) the attempt of one or more unauthorized persons to gain control of an aircraft, (b) an aircraft emergency which prevents proper pilot control and (c) in-flight pilot impairment or incapacity. “Anti-hijacking” refers to the prevention or remedy of a hijacking as defined hereinabove.
Modification of an aircraft, after certification of the type, is extremely time consuming and expensive. Even a seemingly insignificant change in the control system of an aircraft must be modeled, tested and must undergo certification by the Federal Aviation Administration (FAA). It is therefore difficult to retrofit an improvement in an aircraft control system once the aircraft has been constructed and certified as airworthy.